Lens.



'WILLIAM THOMAS coULsoN, or PENGE, ENGLAND.

" LENS.

Specification ot Letters Patent.

Application filed September 17, 1910. Serial No. 582,498.

To all whom it may concern Be it known that I, WILLIAM THOMAS CotYLsoN, a subject of the King of Great Britain, residing at Penge, England, have invented new and useful Improvements in Lenses, of which the following is a specification.

This invention relates to that class of lamp -lens in which the reflection from the internal surface of the glass is utilized.

The lens consists of a truncated cone or conoid of glass or other suitable substance pierced by a hole the axis of the cone and the hole being coincident. The illuminant is placed in the central hole. The slant surface of the cone or conoid forms the reflector. The contours of the conic surface, the base or front of the lens and the central hole may vary considerably to suit different conditions.

The following are examples z-Figure 1 gives an axial sect-ion of a form in which the conoid reflecting surface is spherical or parabolic the base or front indented with circular steps and the hole cylindrical. Fig. 2 shows a form in which the steps are reduced to a slanting or conical surface. Fig.

' 3 shows a form in which the slant is leveled so that the front of the lens becomes flat.

In each Figs. 1, 2 and 3 the axis of the lens lies within the cutting plane making the section.

It is found advisable in some eases to manfacture the lens in two or more sections, the planes of cleavage preferably containin the axis of the lens. A front elevation o one such arrangement is shown in Fig. 4 and one portion or section in Fig. 5.

For ease of manufacture or other reason it might be advisable to modify the shape of the sections; for example they might be constructed with lane surfaces only. Such a lens is shown m front elevation in Fig. 6, and a single section of it in Fig. '7.

Suitable means may be employed to secure the sections in their relative positions and the whole lens whether in one piece or in sections may be suitably inclosed. Many kinds of illuminant may be employed, perhaps electric glow lamps and incandescent cgzlil gas burners are among'the most suita e.

Fig. 8 is a diagrammatic view illustrating one way in which the invention may be utilized practically. In this instance, I represents an illuminating device which may be of any suitable form. This illuminating de- Patented Dec. 9, 1913.

vice is placed within the axially-arranged` hole in the lens and the direct light rays a from the illuminating device proceed to the surface of the lens which surface acts as a reflector whereby the reflected rays a. are directed forwardly. In this figure of the drawin the illuminating device is so placed with re erence tothe lens surface that the reflected rays a will be arranged substantially in parallelism. It will be obvious,

however, that by shifting the illuminating device I rearwardly or toward the lens surface the reflected rays a will diverge as they proceed from the lens and, conversely, by shifting the illuminating device I forwardly or in a direction from the lens surface x, the reflected rays a will converge as they proceed from the lens. Any desired degree of divergence or convergence of the reflected rays can be obtained by suitably adjusting the position of the illuminating device in the axial hole ofthe lens.

The invention may be used advanous kinds, the rear surface of the lens acting as a reflector. This surface of the lens is protected and avoids the necessity of frequent cleaning asis necessary when ordinary mirrors are used and, moreover, the mass of the lens is such that it will be capable of withstanding most shocks that would break or damage ordinary mirrors.

' What I do claim as my invention and desire to secure by Letters Patent is 1. A lens reflector the body of which is provided with a hole extending entirely therethrough to accommodate an illuminating device and operative to project light rays in parallelism therefrom.y

2. A lens reectorchaving a hole extending axially therethrough to accommodate an illuminating device and operative to project light ra s in parallelism therefrom.

3. A ens reflector having a hole extending therethrough coincident with the optica-l axis of the lens to accommodate an illuminatin device and operative to project light rays 1n parallelism therefrom.

4. The combination of a lens having a hole extending axially therethrough, and an illuminating device positioned in said hole, the rays from the illuminating device bein relected in parallelism by a surface o the ens.

5. A lens reflector composed of a plurality '80 .tageously as a reflector for lamps of vari-- of sections united on planes Which'inter'seot the axis of the lens, the latter being provided with a hole which extends axlally therethrouh, and the lens being ogrative i omen 5 to project In testimony ght rays in parallelism illuminatingdevice located in said hole. Y

whereof I have hereunto set PERCY E. Murrocxs, F. C. SMITH. 

